WO2023214478A1

WO2023214478A1 - Conveyance system

Info

Publication number: WO2023214478A1
Application number: PCT/JP2023/009682
Authority: WO
Inventors: 耕太郎柴田
Original assignee: 村田機械株式会社
Priority date: 2022-05-02
Filing date: 2023-03-13
Publication date: 2023-11-09

Abstract

This conveyance system comprises a conveyance vehicle that conveys articles with respect to a passive apparatus and that has a communication unit which communicates wirelessly with the passive apparatus. The conveyance vehicle has a counter that generates a counter value according to the amount of time passed since a time at which reception became impossible due to a communication failure during wireless communication with the passive apparatus, and an output unit that outputs the counter value when a time-out malfunction has occurred in the conveyance vehicle. When reception is possible, the counter perpetually resets the counter value.

Description

Conveyance system

The present disclosure relates to a conveyance system.

In semiconductor manufacturing factories and the like, a transport system having a transport device for automatically transporting manufactured objects to semiconductor manufacturing equipment and the like is used. In such a transport system, signals are exchanged between a transport device that transports a product to be manufactured, and a semiconductor manufacturing device or the like. If this signal exchange is not performed normally for a predetermined period of time, a timeout error occurs. For example, Patent Document 1 listed below discloses a communication device connected to manufacturing equipment that can store data for analyzing the cause of error occurrence. In this communication device, time data including the time when predetermined packet data received by the communication section was transmitted and the time when the predetermined port state was detected by the IO monitor section is accumulated in the storage section. By using this time data, it is determined whether or not the transport control needs to be corrected.

Japanese Patent Application Publication No. 2016-118845

If a timeout error occurs in signal exchange between a transport device that transports a workpiece and semiconductor manufacturing equipment, etc., it is not possible to use only the time data as shown in Patent Document 1 above. It has been difficult to determine whether the problem is caused by the transmission of signals by semiconductor manufacturing equipment or the like.

An object of one aspect of the present disclosure is to provide a transport system that can support determination of the cause of a timeout abnormality.

A conveyance system according to one aspect of the present disclosure is a conveyance system that conveys an article to a passive device and includes a conveyance vehicle having a communication unit that wirelessly communicates with the passive device, wherein the conveyance vehicle wirelessly communicates with the passive device. The counter has a counter that generates a counter value according to the elapsed time from the timing when reception is no longer possible due to a communication failure during communication, and an output section that outputs the counter value when a timeout abnormality occurs in the guided vehicle. always resets the counter value when reception is possible.

In the conveyance system according to one aspect of the present disclosure, the operator can check the cause of the timeout abnormality by simply checking the counter value output from the output unit (that is, checking whether the counter value has been reset). It becomes possible to estimate whether it is a communication abnormality or a passive device abnormality. If the counter value is 0 at the time when the timeout abnormality occurs in the transport vehicle, the operator can understand that wireless communication was being performed normally, and it can therefore be assumed that the cause of the timeout abnormality is in the passive device. On the other hand, if a counter value equal to or higher than a certain value is output at the time when a timeout abnormality occurs in the transport vehicle, the operator can know that wireless communication has not been performed for a certain period of time. Therefore, it can be inferred that the cause of the timeout abnormality is a communication failure. According to such a transport system that can generate and output the above-mentioned counter value, it is possible to support determination of the cause of occurrence of a timeout abnormality.

The wireless communication between the guided vehicle and the passive device is E84 signal wireless communication specified by the international standard for semiconductor manufacturing equipment, and the output section outputs the counter value only when a timeout error occurs due to the E84 signal. It's okay. In this case, generation and output of counter values during unnecessary periods can be prevented. Thereby, it is possible to reliably output a counter value useful for determining the cause of occurrence of a timeout abnormality.

According to one aspect of the present disclosure, it is possible to provide a transport system that can support determination of the cause of occurrence of a timeout abnormality.

FIG. 1 is a plan view of a conveyance system according to an embodiment. FIG. 2 is a front view of a portion of the transport system. FIG. 3 is a schematic diagram showing communication between the overhead transport vehicle and the semiconductor processing equipment. Each of FIGS. 4A and 4B is a timing chart for explaining a normal example of wireless communication between the overhead transport vehicle and the semiconductor processing device. Each of FIGS. 5A and 5B is a timing chart for explaining a normal example of wireless communication between the overhead transport vehicle and the semiconductor processing device. Each of FIGS. 6A and 6B is a timing chart for explaining an abnormal example of wireless communication between the overhead transport vehicle and the semiconductor processing device. Each of FIGS. 7A and 7B is a timing chart for explaining an abnormal example of wireless communication between the overhead transport vehicle and the semiconductor processing device.

Hereinafter, embodiments according to one aspect of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are given the same reference numerals, and redundant description will be omitted.

First, the conveyance system according to this embodiment will be explained with reference to FIGS. 1 and 2. FIG. 1 is a plan view of a conveyance system according to this embodiment. FIG. 2 is a front view of a portion of the transport system. As shown in FIG. 1, a transport system 1 is installed, for example, in a semiconductor manufacturing factory equipped with a semiconductor processing device 100, which is one of passive devices, and is used for transporting articles such as FOUPs (objects to be transported) 200. It is a system. The FOUP 200 is a container (FOUP: Front Opening Unified Pod) that stores semiconductor wafers. The semiconductor processing apparatus 100 is a processing apparatus for the semiconductor wafers (for example, a cleaning apparatus, an etching apparatus, a film forming apparatus, etc.), and includes an apparatus port 110 for loading and unloading the FOUP 200.

As shown in FIGS. 1 and 2, the transport system 1 includes a first track 10, a second track 20, a storage shelf 30, and a plurality of ceiling transport vehicles 40 (transport vehicles). In the transfer system 1, the FOUP 200 is transferred to the device port 110 of the semiconductor processing device 100 by the overhead carrier 40 that moves along the first track 10 or the second track 20, for example. Although not shown, the transport system 1 further includes, for example, a HOST and an MCS (Material Control System) as control devices. Each of the HOST and MCS is an electronic control unit configured with, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). HOST is a higher level controller. HOST may be an MES (Manufacturing Execution System). The HOST outputs a signal (hereinafter simply referred to as a "command") including various commands such as a transport command and a travel command to the MCS. Upon acquiring the command from the HOST, the MCS outputs the command to the ceiling transport vehicle 40 or the like at a predetermined timing via the transport vehicle controller.

The first track 10 is a member (traveling path) on which the ceiling transport vehicle 40 travels, and is suspended from the ceiling. In this embodiment, the transport system 1 includes a plurality of systems (bays). The transport system 1 includes a plurality of intra-bail routes that are travel routes within a bay, and inter-bail routes that are travel routes that connect different bays. Intra bay routes are located along a plurality of device ports 110. The first track 10 includes an intrabay track 11 arranged in a plurality of intrabay routes, and an interbay track 12 arranged in an interbay route. The intrabay track 11 is a track that passes near the storage shelves 30, the semiconductor processing equipment 100, etc., and is set so that the overhead transport vehicle 40 travels one-way clockwise. Similarly to the intrabay track 11, the interbay track 12 is also set so that the overhead transport vehicle 40 travels one-way clockwise. In addition, in the 1st track|orbit 10, the ceiling conveyance vehicle 40 may be set so that it may pass in one direction counterclockwise.

The second track 20 is a member (traveling path) on which the ceiling transport vehicle 40 travels, and is suspended from the ceiling. The second track 20 includes an intrabay track 21 arranged in a part of a plurality of intrabay routes, and an interbay track 22 arranged in an interbay route. The intrabay track 21 is a track that passes near the storage shelves 30, the semiconductor processing equipment 100, etc., and is set so that the overhead transport vehicle 40 travels one-way clockwise. Like the intrabay track 21, the interbay track 22 is also set so that the overhead transport vehicle 40 travels one-way clockwise. In addition, in the second track 20, the ceiling transport vehicle 40 may be set to travel in one direction counterclockwise.

As shown in FIG. 2, the first track 10 and the second track 20 are arranged side by side in the vertical (vertical) direction. The first track 10 is located below the second track 20. In other words, the second orbit 20 is located above the first orbit 10. In FIG. 1, the first trajectory 10 is shown by a broken line, and the second trajectory 20 is shown by a solid line.

As shown in FIG. 1, in the transport system 1, the device ports 110 of each semiconductor processing device 100 are arranged outside Intra-Beirut along the direction in which the first track 10 and the second track 20 extend. There is. Each device port 110 is provided so as to be located on one side and below the first track 10 and second track 20 that are arranged vertically in parallel.

The FOUPs 200 transferred from the ceiling transport vehicle 40 are placed on the plurality of device ports 110, and the FOUPs 200 are transferred to the semiconductor processing device 100. Furthermore, when the semiconductor wafers housed in the FOUPs 200 are processed in the semiconductor processing equipment 100, the plurality of device ports 110 transfer the FOUPs 200 from the semiconductor processing equipment 100 and set the FOUPs 200 thereon. Become.

The storage shelf 30 is a member that stores the FOUPs 200. A plurality of storage shelves 30 support FOUPs 200. For example, the storage shelf 30 is suspended from the ceiling. The storage shelf 30 may be an OHB (Overhead Buffer). A FOUP 200 can be placed in the area on the storage shelf 30. The area of the storage shelf 30 is a temporary storage area where the ceiling transport vehicle 40 that has stopped on the first track 10 and the second track 20 can transfer the FOUP 200.

As shown in FIG. 2, the plurality of storage shelves 30 are provided on the other side and below the first track 10 and the second track 20, the one in which the plurality of device ports 110 are provided. ing. That is, the plurality of storage shelves 30 are provided on the side facing the plurality of device ports 110 via the first track 10 and the second track 20 when viewed from the vertical direction. The storage shelf 30 is provided inside the loop-shaped intrabeirut.

The ceiling transport vehicle 40 is a device that transports the FOUP 200 in areas where it may interfere with passive devices such as the storage shelves 30 and the semiconductor processing equipment 100, and moves along the first track 10 or the second track 20. The overhead transport vehicle 40 includes, for example, a ceiling-suspended crane, an OHT (Overhead Hoist Transfer), and the like. The ceiling transport vehicle 40 includes a grip section 41, a lifting mechanism 42, a moving mechanism 43, a controller 44, and a communication section 45.

The gripping unit 41 is a device that grips and releases the FOUP 200. The grip part 41 can grip the flange part 210 of the FOUP 200. The gripping portion 41 grips the flange portion 210 of the FOUP 200 when the ceiling transport vehicle 40 acquires the FOUP 200 from the device port 110 or the storage shelf 30. The grip part 41 releases the flange part 210 of the FOUP 200 when the ceiling transport vehicle 40 places the FOUP 200 on the device port 110 or the storage shelf 30.

The lifting mechanism 42 is a device (such as a hoist) that raises and lowers the grip portion 41 in the vertical direction. The elevating mechanism 42 is capable of elevating and lowering the grip portion 41 in the vertical direction. The lifting mechanism 42 includes a winding mechanism 42a and a belt 42b. The hoisting mechanism 42a is held by a moving mechanism 43. The winding mechanism 42a is a device that winds up and unwinds the belt 42b in the vertical direction. The winding mechanism 42a is capable of winding up and down the belt 42b in the vertical direction. The belt 42b is suspended from the winding mechanism 42a. The belt 42b holds the grip portion 41 at its lower end. The elevating mechanism 42 is capable of lifting and lowering the FOUP 200 held by the gripping part 41 a distance sufficient to reach at least the device port 110 and the storage shelf 30.

The moving mechanism 43 is a device that moves the grip part 41 and the lifting mechanism 42 along the side of the ceiling transport vehicle. That is, the moving mechanism 43 can move the grip portion 41 and the lifting mechanism 42 from the ceiling carrier 40 in a horizontal direction perpendicular to the traveling direction of the ceiling carrier 40. The moving mechanism 43 is capable of moving the grip portion 41 and the lifting mechanism 42 above the device port 110 and the storage shelf 30, respectively. When the FOUP 200 is gripped by the gripper 41, the moving mechanism 43 can move the FOUP 200 vertically above the device port 110 and the storage shelf 30.

Each of the plurality of overhead transport vehicles 40 that has stopped at the same position in the traveling direction on each of the first track 10 and the second track 20 is located to the side and below the first track 10 and the second track 20. The FOUP 200 can be transferred to both the device port 110 and the storage shelf 30. In other words, each ceiling carrier 40 can transfer the FOUP 200 to the same device port 110 and the same storage shelf 30. That is, the FOUP 200 can be delivered (transferred) to and from the device port 110 in both the ceiling carrier 40 on the first track 10 and the ceiling carrier 40 on the second track 20. In addition, the FOUP 200 can be transferred to and from the storage shelf 30 in both the ceiling transport vehicle 40 on the first track 10 and the ceiling transport vehicle 40 on the second track 20.

The ceiling transport vehicle 40 operates the moving mechanism 43 from a state where the grip part 41 grips the flange part 210 of the FOUP 200 directly below the first track 10 and the second track 20 to move the FOUP 200 to the device port 110 and the storage shelf. 30 above each. Subsequently, the ceiling transport vehicle 40 operates the hoisting mechanism 42a to unwind the belt 42b, lowers the FOUP 200, and places it on the device port 110 or the storage shelf 30. As described above, the ceiling transport vehicle 40 transfers (places) the FOUP 200 onto the device port 110 and the storage shelf 30.

Further, the ceiling transport vehicle 40 grips the flange portion 210 of the FOUP 200 placed on the device port 110 or the storage shelf 30 with the grip portion 41 . Subsequently, the ceiling conveyance vehicle 40 operates the hoisting mechanism 42a to hoist the belt 42b and raise the FOUP 200. Subsequently, the ceiling transport vehicle 40 operates the moving mechanism 43 to move the FOUP 200 directly below the first track 10 and the second track 20. As described above, the ceiling transport vehicle 40 transfers (acquires) the FOUP 200 from the device port 110 or the storage shelf 30.

The controller 44 is a device that controls the operation of the overhead transport vehicle 40. The controller 44 is an electronic control unit including, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The controller 44 communicates with the target semiconductor processing device 100 in response to commands from the control device, and controls the traveling of the ceiling transport vehicle 40, the operation of the gripping section 41, the operation of the lifting mechanism 42, the operation of the moving mechanism 43, etc. Control.

The communication unit 45 is a device that can communicate with the control device, the semiconductor processing device 100, etc., and is arranged at a predetermined position of the overhead transport vehicle 40. FIG. 3 is a schematic diagram showing communication between the overhead transport vehicle and the semiconductor processing equipment. As shown in FIG. 3, the semiconductor processing apparatus 100 includes a communication section 101 capable of communicating with the transport system 1, and a controller 102 connected to the communication section 101. The controller 44 and the communication section 45 transmit and receive data to and from each other. Similarly, the communication unit 101 and the controller 102 also transmit and receive data to and from each other.

The communication unit 45 transmits and receives signals to and from the semiconductor processing device 100 via wireless communication. In this embodiment, the communication section 45 of the overhead transport vehicle 40 and the communication section 101 of the semiconductor processing apparatus 100 communicate with each other wirelessly. The wireless communication between the overhead transport vehicle 40 and the semiconductor processing device 100 is, for example, the transmission and reception of wireless signals performed when the FOUP 200 is transferred. The transfer of the FOUP 200 includes both the transfer of the FOUP 200 from the overhead carrier 40 to the semiconductor processing equipment 100 and the transfer of the FOUP 200 from the semiconductor processing equipment 100 to the ceiling carrier 40. During wireless communication between the overhead transport vehicle 40 and the semiconductor processing device 100, the wireless signals transmitted and received by the

communication units

45 and 101 limit the operation of the semiconductor processing device 100 (in particular, the operation of the device port 110), for example. This is an interlock signal for The interlock signal is, for example, a signal (E84 signal) exchanged according to a procedure defined by E84 of the international standard for semiconductor manufacturing equipment (SEMI standard: Semiconductor Equipment and Materials International standards). By properly transmitting and receiving the E84 signal between the ceiling transport vehicle 40 and the semiconductor processing device 100, the gripping portion 41, the lifting mechanism 42, etc. of the ceiling transport vehicle 40 and the semiconductor processing device 100 are prevented from coming into contact with each other at an unintended location. Interference (contact, collision, etc.) can be prevented. The wireless communication between the overhead transport vehicle 40 and the semiconductor processing device 100 is, for example, ANT communication using frequencies in the 2.4 GHz band and 5.8 GHz band, but is not limited thereto.

According to the procedure defined in E84 described above, the signal that the semiconductor processing device 100 transmits to the ceiling transport vehicle 40 changes, and the ceiling transport vehicle 40 receives the changed signal via the communication unit 45. Hereinafter, a signal transmitted from the semiconductor processing device 100 to the ceiling transport vehicle 40 will be referred to as an output signal, and a signal input from the semiconductor processing device 100 to the ceiling transport vehicle 40 will be referred to as an input signal. Furthermore, the communication unit 101 and the communication unit 45 constantly transmit and receive received signal strengths to and from each other in addition to the E84 signal. The received signal strength is an index that can confirm the state of the communication environment.

If the input signal input to the ceiling transport vehicle 40 does not change over a predetermined period (timeout determination period), the controller 44 determines that a timeout abnormality has occurred. A timeout abnormality occurs due to, for example, a communication abnormality, a device abnormality, or the like. A communication abnormality occurs, for example, due to a communication failure (an abnormality in the communication environment) due to interference from signals generated from other devices. The received signal strength at the time of communication abnormality is considered to be 0. The device abnormality occurs due to, for example, a failure of the semiconductor processing device 100. When a timeout abnormality occurs, the operation between the overhead transport vehicle 40 and the semiconductor processing apparatus 100 (for example, the operation of transferring the FOUP 200) is stopped. Note that, hereinafter, a state in which no communication abnormality occurs during E84 communication between the overhead transport vehicle 40 and the semiconductor processing device 100 may be referred to as a "normal communication state."

As shown in FIG. 3, the overhead transport vehicle 40 includes a counter 46 and an output section 47 in addition to a controller 44 and a communication section 45. The counter 46 and the output section 47 may be part of the controller 44.

The counter 46 starts counting (generates a counter value) from the timing when a communication abnormality occurs during wireless communication between the overhead transport vehicle 40 and the semiconductor processing device 100. In this embodiment, the value counted according to the elapsed time corresponds to the counter value. The counter value may be a value that changes according to a predetermined rule according to the elapsed time. In this embodiment, the counter value is the elapsed time itself. The counter 46 resets the counter value when the communication abnormality is resolved after the counter value is generated (that is, when the received signal strength indicates a value other than 0). Thereby, the counter value indicates the period during which the communication is in the latest abnormal state. In addition, the operator can easily identify the time at which the abnormal communication state occurred from the output counter value. Note that the counter 46 always resets the counter value when reception is possible (for example, when the communication state is normal and the overhead transport vehicle 40 is able to receive the wireless signal from the semiconductor processing device 100).

The output unit 47 outputs the counter value generated by the counter 46 to the controller 44 or the like when a timeout abnormality occurs. In this embodiment, a timeout abnormality is defined as a state in which the overhead transport vehicle 40 is unable to recognize a change in the output signal of the semiconductor processing device 100 within a predetermined period. A state in which the overhead transport vehicle 40 cannot recognize a change in the output signal of the semiconductor processing device 100 corresponds to a state in which the input signal does not change. The output unit 47 outputs the counter value only when a timeout abnormality occurs. As a result, for example, when the overhead transport vehicle 40 and the semiconductor processing device 100 are not exchanging E84 signals, the output unit 47 will not output the counter value even if the counter value is generated.

Next, referring to FIGS. 4A and 4B and FIGS. 5A and 5B, an example ( Normal cases) will be explained. (a), (b) of FIG. 4 and (a), (b) of FIG. 5 are timing charts for explaining a normal example of wireless communication between the overhead transport vehicle 40 and the semiconductor processing device 100. . In each of (a), (b) of FIG. 4 and (a), (b) of FIG. 5, timing T0 indicates the start timing of the timeout determination period, timing T1 indicates the end timing of the timeout determination period, and timing Each of Ts, Ts ₁ and Ts ₂ indicates the timing at which a communication abnormality occurs, the timing Te indicates the end timing of the communication abnormality, the broken line arrow indicates a normal communication state, and the area surrounded by the broken line indicates a communication abnormality state. . In each of FIGS. 4A and 4B and FIGS. 5A and 5B, the initial value of the output signal is the value PL, and the initial value of the input signal is the value CL. The value PL of the output signal changes to the value PH at timing Tp between timing T0 and timing T1. This change from value PL to value PH is performed, for example, by the controller 102 of the semiconductor processing apparatus 100. Further, the change of the input signal from the value CL to the value CH is performed by receiving the output signal having the value PH. Therefore, unless the ceiling transport vehicle 40 receives an output signal having the value PH, the input signal is not updated.

In the first normal example shown in FIG. 4(a), wireless communication between the overhead transport vehicle 40 and the semiconductor processing device 100 is performed normally throughout the timeout determination period. In this case, at the timing Tp, the input signal normally changes from the value CL to the value CH in response to the change of the output signal from the value PL to the value PH. In this case, the controller 44 determines that no timeout abnormality has occurred.

In the second normal example shown in FIG. 4(b), the normal communication state continues at least from timing T0 to timing Tp. Furthermore, a communication abnormality occurs after timing Tp and before timing T1. In this case, similarly to the first normal example, the input signal changes from the value CL to the value CH in response to the change of the output signal from the value PL to the value PH, and the input signal changes normally. Then, as in the first normal example, the controller 44 determines that no timeout abnormality has occurred. Note that the counter 46 generates a counter value from timing Ts after timing Tp. However, in the second normal example, it is determined that no timeout abnormality occurs, so the output unit 47 does not output the counter value. Note that even after timing T1 has passed, the counter 46 may continue counting while the communication abnormality continues.

In the third normal example shown in FIG. 5(a), an abnormal communication state occurs between timing T0 and timing Tp. The communication abnormal state continues until timing Te between timing Tp and timing T0. In addition, the normal communication state continues from timing Te to timing T1. In this case, the input signal does not change from timing Tp to timing Te. However, when the output signal indicating the value PH is received by the overhead transport vehicle 40 in a normal communication state after the timing Te, the input signal changes normally. Then, similarly to the first normal example and the second normal example, the controller 44 determines that no timeout abnormality has occurred. Note that the counter value is generated by the counter 46 between timing Tp and timing Te, but the counter value is reset at timing Te. The counter value may be reset between timing Te and timing T1. The same applies to the following examples.

In the fourth normal example shown in FIG. 5(b), similarly to the third normal example, a communication abnormality occurs from timing _Ts1 , which is between timing T0 and timing Tp. Further, the communication abnormal state continues until timing Te between timing Tp and timing T0. In addition, another abnormal communication state occurs from timing _Ts2 to timing T1, which is later than timing Te. In this case, similarly to the third normal example, the input signal is not updated at timing Tp. However, in a normal communication state existing between timing Te and timing _Ts2 , an output signal indicating the value PH is received by the overhead carrier 40. This causes the input signal to change normally. Then, similarly to the first to third normal examples, the controller 44 determines that no time-out abnormality has occurred. Note that the counter value is generated by the counter 46 between timing Ts ₁ and timing Te, but the counter value is reset at timing Te. However, from timing _Ts2 , a new counter value is generated by the counter 46. However, in the fourth normal example, it is determined that no time-out abnormality occurs, so no new counter value is output. Note that generation of the new counter value by the counter 46 may be continued until the communication abnormality that occurred at timing _Ts2 is resolved.

Next, referring to FIGS. 6A and 6B and FIGS. 7A and 7B, an example of when the overhead transport vehicle 40 and the semiconductor processing equipment 100 cannot communicate normally (Abnormal example) will be explained. (a), (b) of FIG. 6 and (a), (b) of FIG. 7 are timing charts for explaining an abnormal example of wireless communication between the overhead transport vehicle 40 and the semiconductor processing device 100. .

In the first abnormal example shown in FIG. 6(a), wireless communication between the overhead transport vehicle 40 and the semiconductor processing device 100 is performed normally throughout the timeout determination period. Therefore, the counter value of the counter 46 does not change from 0. On the other hand, the value of the output signal remains PL from timing T0 to timing T1. Therefore, the input signal does not indicate the value CH by timing T1, and the controller 44 determines that a timeout abnormality has occurred. In this case, the output unit 47 outputs a counter value of 0. For example, the controller 44 outputs the counter value as log information.

In the second abnormal example shown in FIG. 6(b), the communication is in an abnormal state throughout the timeout determination period. The counter 46 generates a counter value from the time when reception is no longer performed until reception is performed again. On the other hand, the value of the output signal changes to the value PH at timing Tp, but the value of the input signal remains at the value CL from timing T0 to timing T1. Therefore, similarly to the first abnormality example, the controller 44 determines that a timeout abnormality has occurred. In this case, the output unit 47 outputs the counter value at timing T1. Note that the minimum counter value assumed in the second abnormal example corresponds to the elapsed time from timing T0 to timing T1. If the communication abnormality occurs before timing T0, the counter value is larger than the elapsed time from timing T0 to timing T1. Even when both a device abnormality and a communication abnormality occur, generation of the counter value starts from the time when the communication abnormality occurs.

In the third abnormal example shown in FIG. 7(a), the communication abnormal state continues from before timing Tp until timing T1. In this case, the counter 46 generates a counter value from timing Ts between timing T0 and timing Tp. On the other hand, similarly to the first abnormal example and the second abnormal example, the value of the input signal remains at the value CL from timing T0 to timing T1. Therefore, similarly to the first abnormal example and the second abnormal example, the controller 44 determines that a timeout abnormality has occurred. In this case, the output unit 47 outputs the counter value at timing T1. The counter value output in the third abnormal example corresponds to the elapsed time from timing Ts to timing T1. Note that even when a device abnormality occurs after timing Ts, the output counter value corresponds to the elapsed time from the time when the communication abnormality occurs (timing Ts) to timing T1.

In the fourth abnormality example shown in FIG. 7(b), a plurality of communication abnormal states occur intermittently between timing T0 and timing T1. In the fourth abnormality example, the first abnormal communication state continues from timing Ts ₁ to timing Te, and the second abnormal communication state continues from timing Ts ₂ after timing Te to timing T1. In this case, the counter value generated by the counter 46 in the first abnormal communication state is reset at timing Te. Further, the counter 46 generates a new counter value from timing _Ts2 . On the other hand, the value of the input signal remains at the value CL from timing T0 to timing T1, similarly to the first to third abnormal examples. Therefore, similarly to the first to third abnormal examples, the controller 44 determines that a timeout abnormality has occurred. In this case, the output unit 47 outputs the new counter value at timing T1. The counter value output in the fourth abnormality example corresponds to, for example, the elapsed time from timing _Ts2 to timing T1.

The counter value output when a timeout abnormality occurs in each abnormality example can be used as an index for estimating the cause of the timeout abnormality. For example, if the counter value output by the output unit 47 is 0 (i.e., in the case of the first abnormality), the worker can determine that there is no problem in the communication environment between the overhead transport vehicle 40 and the semiconductor processing device 100. can be easily understood. Thereby, the operator can infer that the timeout abnormality has occurred due to a device abnormality.

When the counter value output by the output unit 47 is other than 0 (that is, in the case of the second to fourth abnormal cases), the operator can determine the cause of the timeout abnormality by checking the output counter value. can be estimated. For example, by checking the output counter value, the operator can easily estimate whether a normal communication state existed between timing T0 and timing T1. Based on such estimation, the operator can estimate whether the cause or main cause of the timeout abnormality in each of the second to fourth abnormal cases is a communication abnormality or a device abnormality.

Specifically, when a timeout abnormality occurs, the operator determines the length of the timeout determination period (from timing T0 to timing T1), the output counter value, and the signal state of the overhead carrier 40 at the time the timeout abnormality occurs. (value CL, value CH). Note that although the timing Tp is illustrated for convenience in FIGS. 6 and 7, the timing Tp cannot be grasped by the operator. When the output counter value is 0 (first abnormality example), the operator can estimate that no communication abnormality has occurred and that a device abnormality has occurred. When the output counter value is greater than or equal to the timeout judgment period (second abnormality example), the worker is informed that a communication error has always occurred during the timeout judgment period, or that a communication error has occurred before the timeout judgment started. can be estimated. In this case, there is a possibility that a device abnormality also occurs while a communication abnormality occurs. When the output counter value is smaller than the timeout judgment time (third abnormality example, fourth abnormality example), the length of the period during which the communication abnormality occurred can be determined from the size of the output counter value, and the device The degree of possibility of an abnormality can be estimated.

In the transport system 1 according to the embodiment described above, the operator can check whether the cause of the timeout abnormality is a communication abnormality or not by simply checking the counter value output from the output unit 47. It becomes possible to estimate whether there is a device abnormality. Therefore, according to the transport system 1, it is possible to support determination of the cause of occurrence of the timeout abnormality.

In this embodiment, the wireless communication between the overhead transport vehicle 40 and the semiconductor processing equipment 100 is E84 signal wireless communication specified by the international standard for semiconductor manufacturing equipment, and the output unit 47 detects a timeout error of the E84 signal. The counter value may be output only when it occurs. In this case, generation and output of counter values during unnecessary periods can be prevented. Thereby, it is possible to reliably output a counter value useful for determining the cause of occurrence of a timeout abnormality.

As described above, the conveyance system according to one aspect of the present disclosure is as described in [1] to [6] below, and these have been explained in detail based on the above embodiments.
[1] A transport system that transports articles to a passive device and includes a transport vehicle having a communication unit that wirelessly communicates with the passive device,
The transport vehicle is
a counter that generates a counter value according to the elapsed time from the timing when reception became impossible due to a communication failure during wireless communication with the passive device;
an output unit that outputs the counter value when a timeout abnormality occurs in the guided vehicle;
the counter always resets the counter value when reception is possible;
Conveyance system.
[2] The wireless communication between the transport vehicle and the passive device is E84 signal wireless communication specified in the international standard for semiconductor manufacturing equipment,
The conveyance system according to [1], wherein the output unit outputs the counter value only when a timeout abnormality due to the E84 signal occurs.
[3] The conveyance system according to [1] or [2], wherein the counter value is the elapsed time itself.
[4] The transport system according to any one of [1] to [3], wherein the timing corresponds to a timing at which a communication abnormality occurs between the transport vehicle and the passive device.
[5] The transport system according to any one of [1] to [4], wherein the timeout abnormality occurs when the transport vehicle fails to recognize a change in the output signal of the passive device within a predetermined period. .
[6] The transport system according to any one of [1] to [5], wherein the counter always resets the counter value during wireless communication between the transport vehicle and the passive device.

However, one aspect of the present disclosure is not limited to the above embodiments and [1] to [6] above. One aspect of the present disclosure can be further modified without departing from the gist thereof. For example, in the above embodiment, the transport system is installed in a semiconductor processing factory, but the system is not limited thereto, and may be installed in other facilities. In this case, a processing device that performs some kind of processing on articles is installed in another facility as a passive device. In other facilities, the interlock signal is not limited to the E84 signal. Therefore, in the above embodiments, the passive device is a semiconductor processing device, but is not limited thereto.

In the above embodiment, the first track and the second track are arranged side by side in the vertical (vertical) direction, but the invention is not limited thereto. The overhead carrier may have only one track, or three or more tracks may be arranged side by side. Further, only a portion of the plurality of tracks may be arranged to overlap in the vertical (vertical) direction, or a plurality of tracks with different heights do not need to overlap in the vertical (vertical) direction.

In the above embodiment, the plurality of storage shelves are provided on the side facing the plurality of device ports via the first track and the second track when viewed from the vertical direction, but the invention is not limited thereto. . The processing port and the storage shelf may be located on the same side of the track. Further, the storage shelf may be provided inside the loop-shaped intrabeirut, or may be provided outside.

In the above embodiment, the transport vehicle is an overhead transport vehicle that runs on a track laid on the ceiling of a semiconductor processing factory, but the present invention is not limited to this. The transport vehicle may be a transport vehicle that travels on a track laid on the floor surface, or it may be a transport vehicle that travels directly on the floor surface.

DESCRIPTION OF SYMBOLS 1...Transportation system, 10...First track, 20...Second track, 30...Storage shelf, 40...Ceiling carrier, 41...Gripping part, 42...Elevating mechanism, 43...Movement mechanism, 44...Controller, 45...Communication Department, 100...Semiconductor processing device, 101...Communication department, 102...Controller, 110...Device port, 200...FOUP (article).

Claims

A conveyance system comprising a conveyance vehicle that conveys an article to a passive device and has a communication unit that wirelessly communicates with the passive device,
The transport vehicle is
a counter that generates a counter value according to the elapsed time from the timing when reception became impossible due to a communication failure during wireless communication with the passive device;
an output unit that outputs the counter value when a timeout abnormality occurs in the guided vehicle;
the counter always resets the counter value when reception is possible;
Conveyance system.
The wireless communication between the carrier vehicle and the passive device is E84 signal wireless communication specified in the international standard regarding semiconductor manufacturing equipment,
The conveyance system according to claim 1, wherein the output unit outputs the counter value only when a timeout abnormality occurs due to the E84 signal.
The conveyance system according to claim 1 or 2, wherein the counter value is the elapsed time itself.
The conveyance system according to claim 1 or 2, wherein the timing corresponds to a timing at which a communication abnormality occurs between the conveyance vehicle and the passive device.
The conveyance system according to claim 1 or 2, wherein the timeout abnormality occurs when the conveyance vehicle is unable to recognize a change in the output signal of the passive device within a predetermined period.
The conveyance system according to claim 1 or 2, wherein the counter always resets the counter value during wireless communication between the conveyance vehicle and the passive device.